DerivationFrameworkSUSY: adjust DecorateSUSYProcess.py to cope with new DSID numbering scheme

With the new DSID numbering scheme there are no SUSY DSID blocks anymore, hence it is not trivial anymore to decide whether the sample is a SUSY signal or not. As these are generated with MadGraph, the augmentation with the SUSY final state is performed now for all MG samples (DSID range 500000-599999). Thus, non-SUSY MG samples also get these augmentations (filled with dummy values), but the size increase is marginal (3 ints/event) and should not be problematic.

Tagging also @crizzi